No. If line WX would have been a tangent, the angle VWX should have been 90 degrees. If it would have been 90 degrees, using the pythagoras theorem, side VX should have been 5. But it's not 5, neither angle VWX is 90 degrees nor is the line WX a tangent to the circle
The x-intercept of a function is basically it's roots. So when you factor out the function f(x) = x^2 - 16x + 64 you get
(x-8)(x-8)
x = 8
So x-int. is (0,8) or x = 8
A and P for top are A= 25cm Sq. P= 24cm
A and P for bottom are A= 80yd Sq. P= 38yd